It also makes it harder to interpret ABP results, leaving room for chemical enhancement as well. Remote places, moreover, are harder for out-of-competition testers to reach.

同时它还使得对运动员生物护照(ABP)结果的解释更加困难，为化学增强留下了空间。此外，赛外测试人员很难到达偏远地区。

Such variations, says Dr Tucker, are one reason why the ABP, which tracks changes in an athlete's physiology over time, is difficult to apply to steroid doping.

塔克博士说，由于ABP追踪的是运动员的生理随时间的变化，所以这种自然差异是ABP难以应用于类固醇兴奋剂的原因之一。